# Timeline Editor

Interactive web-based editor for `timeline.seq` files.

## Features

- 📂 Load/save `timeline.seq` files
- 📊 Visual Gantt-style timeline with sticky time markers
- 🎯 Drag & drop sequences and effects
- 🎯 Resize effects with handles
- 📦 Collapsible sequences (double-click to collapse)
- 📏 Vertical grid lines synchronized with time ticks
- ⏱️ Edit timing and properties
- ⚙️ Stack-order based priority system
- 🔍 Zoom (10%-500%) with mouse wheel + Ctrl/Cmd
- 🎵 Audio waveform visualization
- 🎼 Snap-to-beat mode
- 🔄 Re-order sequences by time
- 🗑️ Delete sequences/effects

## Usage

1. **Open:** `open tools/timeline_editor/index.html` or double-click in browser
2. **Load timeline:** Click "📂 Load timeline.seq" → select `workspaces/main/timeline.seq`
3. **Edit:**
   - Drag sequences/effects to reposition
   - Double-click sequence header to collapse/expand
   - Click item to edit properties in side panel
   - Drag effect handles to resize
4. **Zoom:** Ctrl/Cmd + mouse wheel (zooms at cursor position)
5. **Audio:** Load WAV file for waveform visualization
6. **Save:** Click "💾 Save timeline.seq"

## File Format

⚠️ **For complete format specification, see:** `doc/SEQUENCE.md`

The editor parses and generates `.seq` files with this format:

```
# BPM 120
SEQUENCE <start_time> <priority> ["optional_name"] [optional_end]
  EFFECT <+|=|-> <ClassName> <start_time> <end_time> [args...]
  EFFECT <+|=|-> <ClassName> <start_time> <end_time> [args...]
```

**Priority Modifiers:**
- `+` = Increment priority (normal effects)
- `=` = Keep same priority as previous
- `-` = Decrement priority (background layers)

**Time Notation:**
- `0b`, `4b`, `64b` = Beats (converted using BPM)
- `0.0`, `2.0`, `32.0` = Seconds
- Integer without 'b': treated as beats
- Decimal point: treated as seconds

Example:
```
# BPM 120
SEQUENCE 0b 0 "Opening Scene"
  EFFECT - FlashCubeEffect .2 3      # Background (priority -1)
  EFFECT + FlashEffect 0.0 1.0       # Foreground (priority 0)
  EFFECT + FadeEffect 0.5 2.0        # Overlay (priority 1)

SEQUENCE 4b 1 "Beat Drop"
  EFFECT + HeptagonEffect 0.0 0.5    # Priority 0
  EFFECT = ParticlesEffect 0.0 2.0   # Priority 0 (same layer)
```

## Technical Notes

- Pure HTML/CSS/JavaScript (no dependencies, works offline)
- Sequences have absolute times, effects are relative to parent sequence
- Priority determines render order (higher = on top)
- Collapsed sequences show 35px title bar, expanded show full effect stack
- Time markers sticky at top when scrolling
- Vertical grid lines aid alignment